1. Field of the Invention
This invention pertains to a thermoplastic carbonated water distribution manifold for a soft drink beverage dispenser, and to a method of making the manifold.
2. The Prior Art
A post-mix carbonated beverage dispensing system makes its own carbonated water from a supply of municipal or well water, and then distributes the carbonated water to a plurality of post-mix valves. Each post-mix valves mixes carbonated water with syrup and effects dispensing of a complete beverage. These dispensers are typically found in fast food retailers, theatres, convention centers, sports facilities and the like, and are most often used to fill cups with beverage.
Most all of these plural flavor post-mix dispensers have some type of structure to distribute carbonated water from a single source which may be single or plural carbonator to a plurality of dispensing valves. There typically will be a minimum of four dispensing valves and it is common to see up to of four dispensing valves and it is common to see up to twelve dispensing valves being supplied from a single carbonator.
The structure that distributes the carbonated water has been a continual source of problems and a cause of decarbonation and foaming during dispensing. One structure for distributing carbonated water was a molded plastic housing with metal ferrules for an inlet and plural outlets.
These devices had to be located remote from the cooling structure and during stand by time, carbonated water in the housing would warm up and decarbonate. Leakage, ferrule breakage, stress cracks and sanitation were also continually reoccuring problems.
A metal block with a bored out center section, with bored and tapped transverse aperture with adapter fittings has also been used. These are expensive, heavy, bulky, leaky, very difficult to sanitize and are not an effective solution. A typical example is U.S. Pat. No. 3,175,578.
The most recently commercially used structure for distributing carbonated water is a manifold made of an elongate length of stainless steel tubing forming an elongate plenum.
At least one end of the tube is closed and the other end may be an inlet or may be closed. Several transverse fittings are welded into apertures drilled transversely into the plenum tube. The transverse fittings are then welded into the plenum tube. This structure has been in use for several years and is the least costly, and most structurally efficient known device for distributing carbonated water in a dispenser. A typical example of this structure is shown in U.S. Pat. No. 3,892,335.
The problem is that it may or may not properly dispense carbonated water and beverage; you really don't know until the dispenser has been in use for a period of time. The problem results from the welding of the transverse fittings to the plenum tube. The weld usually breaks through at least one of the transverse tubes and causes an obstruction in the tube. Carbonated water flowing over the obstruction then decarbonates and the dispensing valve foams. A given manifold may have five good outlets and one bad outlet; it may have three bad outlets, it may have a bad inlet, it may be perfectly good. Whether the manifold is a good one or a defective one can't be visually determined. Consequently the quality control and quality repeatability of these manifolds is very poor. These manifolds are also a sanitary problem because of crevices in the weld, and/or crevices where the weld has not completely penetrated. The welds in this manifold cannot be viably inspected from the inside. The retailer or beverage entity that ends up with a defective manifold has to go through all kinds of exercise to determine the manifold is defective. Usually dispensing valves will be changed, sanitizing will be done, and a serviceman will attempt to adjust the dispenser.
This is a serious irritant and quality problem for the food and beverage industry. Carbonated water is a very unique and delicate substance to handle, convey and distribute, while preventing decarbonation and resultant foaming of beverage.